Balancing means for shutters intended for use with motion-picture-projection apparatus.



F. C. HAMILTON. BALANCING MEANS FOR SHUTTERS INTENDED FOR USE WITH MOTION PICTURE PROJECTION APPARATUS.

APPLICATION FILED SEPT. 30, I915. 1,210,064.

Patented Dec. 26, 1916 UNITED STATES PATENT OFFICE.

FRANK C. HAMILTON, OF NEW YORK, N. Y., ASSIGNOR TO EUREKA PROJECTOR DEVICE 00., INC., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

BALANCING MEANS FOR SHUTTERS INTENDED FOR USE WITH MOTION-PICTURE- PROJECTION APPARATUS.

Specification of Letters Patent.

Patented Dec. 26, 1916.

Application filed September 30, 1915. Serial No. 53,234.

Tocll whom it may concern:

Be it known that I, FRANK C. HAMILTON, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Balancing Means for Shutters Intended for Use with Motion Picture Projection Apparatus, of which the following is a specification.

This invention relates to the motion pic ture art, and concerns itself particularly with improvements in revolving shutters for use in projecting apparatus.

()ne of the objects of the invention is to provide a shutter in which the usual opaque vanes are replaced by glass sectors, or vanes, which, while transparent, cause a destruction of focus or the diffusion of light rays passing through them, and to arrange for ready and effective assembling of such vanes with the usual revolving shutter shaft of a PIOjBCtll'lg apparatus. Since for certain reasons it is necessary that one of the vanes be larger and of greater weight than the others, and therefore necessary or advisable to balance said greater mass, I aim to provide conveniently adjustable means for quickly ascertaining and establishing the balance.

In the accompanying drawings, which are to be taken as a part of this specification, and in which I have shown a merely preferred form of embodiment of the invention, Figure l is a side elevation of a device including my invention; Fig. 2 is a similar view; but with certain parts removed; Fig. 3 is an enlarged view of a portion of the showing of Fig. 1; and Fig. 4 is a sectional view taken on the line H of Fig. 3;

Similar reference characters refer to sim-' ilar parts.

The numeral 5 indicates a seat member,.

a generally unitary member except for the sleeve 8 when said side shields are riveted subdivisions thereof marked 5*, 5*, 5 5, 5 5, 5 5", and except for the subdivisions 5* and 5 These two last subdivisions are each shown as a solid unit. But the other six subdivisions are each composed of a file of laminae as disclosed most clearly in Fig. 4. Any particular pile may have its mass variously adjusted by removing or re placing any of its laminae; and the various piles are located not only at various radial distances from the center of rotation of the shutter but at various angular distances from the radius of the shutter which in cludes the center line of the heaviest of the vanes, to wit, here assumed to be the uppermost vane in the drawing; thus providing for the maximum flexibility of adjustment. A duplicate pair of side shields 9, each of the outline indicated in Fig. 1, are centrally bored so as also to take about the or bolted to the seat member 5, and maintain said seat member and vanes 6 interlocked, as aforesaid. It will be noted that none of these rivets or bolts 20 pass through any of the vanes. Each vane 6 is thicker in its shank than elsewhere, and the arcuate edges of side shields 9 are inturned against arouate shoulders one carried on each side of each vane and marking the merging of a vane blade into its shank.

A trifurcated fiat spring 10 is riveted to one of said side shields as shown best in Fig. 1. This spring 10 has centrally offset therefrom a sleeve 10 adapted to take about sleeve 8. Sleeve. 10* carries a threaded aperture for :1v set screw 11; the set screw being spirally adjustable so that its shank may pass through sleeve 8s aperture 8 and have the tip of the shank forced tight against the usual revolving shutter shaft 12 (Fig. 1) usually found in projecting apparatus. IVith sleeves 8 and 10 thus mounted fixedly on shaft 12, the shutter is adjusted against end thrust on said shaft by means of a washer 13 and a nut 14 (Fig.4).

A fillet 15 may be employed as shown.

Each of the vanes- 6, instead of being opaque, as usual, is preferably of a trans. parent material which, when halted predeterminedly transversely of the light rays from the illuminator within the projecting apparatus, difiuses said light rays sufficiently. to project onto the usual screen nothing even said inost oi? glass, e molded piece balancing of ise its center of ULGFP poseible of, is of great ii'n ismuch as many in the above construe l Widely? difierent nation could be nadr n. the scope thereof, 21 matter contained in the on or shown in the aceonr shall be interpreted as i 've and not in a limiting sense, it is SW30 to be understood that the language used in the folg claims is intended to cover all the in and specific featr" i ivention described. and e of the rotation l he made any agaparta or my a oeparting ave descrippilee l; I a various locat 3 of rotation of the oeing spaced l i rotation.

rotatable nying drawtroni rality of vanes so arranged that the center oi gravity of said shutter is removed from the center of rotation thereof, an adjustable pile of removable laminae removed from said two centers.

4. In a rotatable shutter carrying a plurality of vanes so arranged that the center of gravity of said shutter is removed from the center of rotation thereof, an adjustable pile of removable laminae removed from said two centers, the pile being built up in a direction parallel with the axis of rotation of the shutterj 5. In a rotatable shutter a plurality of adjustable-piles oi laminae, carried by the shutter at various locations all removed from the center of rotation of the shutter, each of said piles being spaced diderently from said center of rotation, each pile being built up lthe center of rotation thereof, a collection individually removable Weights removed said two centers;

r. 1," ,I l a i V in testimony Whereol lain my signature in presence oi two Witnesses.

FRANK C. llAMlL'llUll. 

